Apparatus for conveying logs axially



Dec. 18, 1962 L. B. SMITH 3,068,918

APPARATUS FOR CONVEYING LOGS AXIALLY 3, --zb-- L31 La 33% -16 INVENTOR. Llo d B. Smbh. BY

Rttor-neys ,United States Patent Filed Nov. 16, 1960, Ser. No. 69,650 7 Claims. (Cl. 144246) This'invention relates to apparatus for conveying logs axially andmore particularly to such apparatus especially adapted for feeding logs axially into or removing them from debarkers or likeapparatus.

In the art of feeding logs to apparatus such as debarkers, it usually is desirable to feed large and small diameter'logsthrough the debarker at different linear rates of speed. Usually, debarkers are made to take a certain range of log sizes, for example. from 4 inches diameter to 24 inches diameter. Since the debarking elementscustomarily rotate at constant speed regardless of the size log being worked on, much time is wasted in debarking logs smaller than the maximum size for which the apparatus is designed unless some means is provided to feed the smaller logs at a faster rate than the larger logs are fed. Therefore, there is currently a need for a simple, rugged apparatus to accomplish the foregoing and especially such apparatus which automatically feeds all logs at the optimum rate.

The prime object of my invention, therefore, is to providesimple, rugged and economical means which automatically feeds all size logs within a range of diameters axially into a debarker or the like at the optimum debarking speeds for each size log.

Another object is to provide apparatus of the character designated which shall feed logs of all sizes within a given range without requiring positive, all around gripping or engagement with the logs, thus facilitating the feeding of crooked logs or those having projections there- Briefly, my invention comprises one or more, preferably two sets of generally conical shaped rollers, mounted alongside each other on vertical shafts. The shafts are driven in unison with adjacent surfaces of the rollers moving in a direction to feed the logs to the debarker, or, if used as discharge means, in a direction to feed the logs away from the debarker. Such roller pairs thus form a trough for the support of the logs. As will appear, when smaller logs are being fed they are engaged by the larger diameter surfaces of the rollers and consequently are fed at a faster axial rate than are larger logs which are engaged by smaller diameter surfaces of the rollers. Thus, by selecting the cone angles or slope of the rollers, I can automatically regulate the axial rate of movement of logs in accordance with their diameters. I preferably roughen or serrate the surfaces of the rollers and provide a gravity or spring biased hold-down roll for the logs to assure positive movement into or out of the debarker.

Apparatus illustrating features of my invention is shown in the accompanying drawing forming a part hereof, in which:

FIG. 1 is a somewhat diagrammatic side elevational view of my improved apparatus on both the infeed and outfeed sides of a ring type debarker, the debarker being shown in wholly diagrammatic manner; I

FIG. 2 is a view taken generally along line 22 of FIG. 1 with the log shown in FIG. 1 and certain of the parts being omitted, and with the outline of the debarker indicated in dotted lines; and,

FIG. 3 is an enlarged elevational view of a pair of the rollers taken generally along line 33 of FIG. 2.

Referring now to the drawing for a better understanding of my invention I show the same in position to both t 13 attached to a part of the debarker ring frame.

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feed logs to and remove them from a ring type debarker. The debarker is indicated in wholly diagrammatic manner by the block D, it being understood that the debarker embodies a rotating part which rotates about the axis of the log, for instance as indicated by the arrow 10. Further, such debarkers generally have means to raise and lower the ring to center the ring relative to logs of different diameters. I have illustrated such means as being a hydraulic cylinder 11 mounted on a fixed support indicated at 12. The hydraulic cylinder has its piston rod y admitting fluid to the lower end of the cylinder from a valve 14, the ring may be raised up and down so as to. center it relative to an oncoming log indicated bythe letter L. A pump 16 supplies fluid under pressure and the usual reservoir 17 is shown diagrammatically.

My improved log feeding and discharge mechanism comprises pairs of generally conical shaped rollers, preferably frusto-conical, each roller of each pair being indicated by the numeral 18 in the drawing. Each roller is mounted on a vertical shaft indicated at 19, the shaft being supported in upper and lower bearings 21 and 22. The pairs of bearings may be braced by suitable members 23 and 24. The lower sets of bearings may be supported on columns 26 resting on the ground or other support indicated at 27.

It will be noted that the rollers 18 are spaced apart a distance less than the diameter of the smallest log to be.

conveyed. Further, the shafts '19 supporting each of the rollers 18 carry intermeshing gears 29. That is to say, eachshaft 19 of each cooperating pair of rollers 18 is provided with one of the gears 29 which engages the gear 29 on the cooperating shaft.

One longitudinal row of each of the shafts 19 may be provided with bevel gears 31. Mounted in suitable bearings is an elongated shaft 32 which carries bevel gears 33 cooperating with gears 31. The shaft 32 may be driven by a motor or the like indicated at 34, whereby the rollers may be driven in unison and at substantially constant speed.

The surfaces of the rollers 18 may be serrated as at 13*, thus to afford good gripping engagement with the logs L. Further, in order to assure good firm driving contact I may provide gravity or spring actuated hold-down rollers indicated at 35 and which may be mounted on arms 36 pivoted at 37 to a stationary support 38. These rollers may be spaced generally between the spaced sets of pairs of the rollers 18.

From the foregoing it will be seen, particularly as shown in FIG. 3, that when a small log L is placed on the rollers 18 it engages the larger diameter surfaces of such rollers. When a larger log L is placed on the rollers it engages smaller diameter surfaces of the rollers. Thus, with the rollers 18 being driven at substantially constant speed, the smaller logs L are fed axially into the debarker at a greater linear rate than are the larger logs L By properly selecting the cone angle for the rollers 18 in accordance with the range of log diameters to be conveyed, I provide means which automatically conveys the entire range of log sizes through the debarker D at the optimum axial rate of speed.

It will be especially noted that the two conical-shaped rollers, with their minor diameters upright, act precisely opposite in conveying effect to the double cone, horizon tally disposed rollers which are so common in log feeding means. In other Words, with the double cone prior art rollers, the larger log engages the larger diameter portions of such rollers; in my improved apparatus the smaller log engages the larger diameter portions of the rollers.

From the foregoing it will be apparent that I have invented an improved, simple and economical feed means for debarkers. It will be understood that by actuating the hydraulic cylinder 11 the debarking ring is moved up or down so that its center coincides with the longitudinal axis of the logs, thus to accommodate the debarker to logs of different diameters. Also, in some cases it is possible to use single sets of the rollers 18 on both the feed and discharge sides of the debarker. In this case the holddown rollers would be placed directly over the pair of feed rollers 13. My improved apparatus is extremely simple of manufacture, trouble free in operation and rugged enough to stand the rough treatment to which this type of machinery is subjected in normal use.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without deparitng from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In apparatus for conveying logs and the like axially, a pair of generally conical-shaped rollers mounted for rotation about substantially vertical axes and with the major diameter surfaces thereof at the bottom and spaced close enough together for the rollers to support therebetween the smallest diameter log of a range of log sizes, and means to drive the rollers substantially in unison in a direction to move a log axially.

2. Apparatus as defined in claim 1 in which the surfaces of said rollers are roughened to increase frictional engagement with the log being conveyed.

3. In apparatus for conveying logs and the like axially, a plurality of horizontally spaced pairs of generally conical shaped rollers, means mounting the pairs of rollers in substantially upright position with the large end of each roller at the bottom and the rollers of each pair spaced close enough each to its associated roller to support a log therebetween, and means to rotate the rollers substantially in unison with adjacent surfaces thereof moving in the desired direction of log travel.

4. Apparatus as defined in claim 3 including log holddown means engaging the upper surface of a log being supported on the rollers.

5. Apparatus as defined in claim 4 in which the log holddown means is in the form of a roller adapted to engage said upper surface of the log.

6. The combination with a rotary head type debarker, of a pair of upright generally conical shaped rollers with their large ends at the bottom, said rollers being spaced apart a distance to engage therebetween the smallest diameter log of a range of log sizes, and means to rotate the rollers substantially in unison and at substantially constant speed with the surfaces of the rollers engaging the log moving in a direction to move the log axially relative to the debarker, whereby smaller diameter logs are moved relative to the debarker at greater axial speed than the larger diameter logs of said range of sizes.

7. Apparatus as defined in claim 6 in which there are a plurality of spaced pairs of said rollers located close enough together to support a log and move it relative to the debarker.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,367 Ahrens Mar. 31, 1925 1,795,137 Nye Mar. 3, 1931 2,625,185 Merry Jan. 13, 1953 2,796,896 Ketonen June 25, 1957 2,821,220 Nicholson Jan. 28, 1958 

